Generally, a transmit power level of an uplink channel from a User Equipment (UE, also commonly referred to as a Mobile Station, Terminal, User, Subscriber, and so forth) to an enhanced NodeB (eNB, also commonly referred to as a Base Station, NodeB, Controller, and so on) may be set at a determined level to achieve a desired level of uplink performance, help maximize battery life of the UE as well as mitigate interference to other UEs and eNBs, as well as other electronic devices, operating in the general vicinity of the UE. Furthermore, the proper setting of the transmit power level may also help improve multiple input, multiple output (MIMO) antenna performance. Setting the transmit power level may often be referred to as power control.
In The Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) Release Eight (Rel-8) technical standards, uplink power control is specified only for single transmit antenna situations. However, in subsequent releases of the 3GPP LTE technical standards, such as Rel-10 and beyond (also known as LTE-Advanced), uplink Single User MIMO (SU-MIMO) also known as spatial multiplexing is introduced and uplink power control needs to be extended to handle situations with UEs having multiple transmit antennas. Uplink power control over multiple transmit antennas is especially important in the case of multiple layer/multiple codeword transmissions.
Currently used techniques for multiple transmit antenna power control involve the use of extensions of existing single transmit antenna power control schemes, which may not provide optimal results in multiple transmit antenna situations.